U.S. patent application number 14/131518 was filed with the patent office on 2014-05-22 for energy application planning apparatus.
This patent application is currently assigned to KONINKLIJKE PHILIPS N.V.. The applicant listed for this patent is Waltherus Cornelis Jozef Bierhoff, Bernardus Hendrikus Wilhelmus Hendriks, Gerhardus Wilhelmus Lucassen, Pieter Maria Mielekamp, Rami Nachabe, Nicolaas Jan Noordhoek, Marjolein Van Der Voort. Invention is credited to Waltherus Cornelis Jozef Bierhoff, Bernardus Hendrikus Wilhelmus Hendriks, Gerhardus Wilhelmus Lucassen, Pieter Maria Mielekamp, Rami Nachabe, Nicolaas Jan Noordhoek, Marjolein Van Der Voort.
Application Number | 20140142563 14/131518 |
Document ID | / |
Family ID | 46727268 |
Filed Date | 2014-05-22 |
United States Patent
Application |
20140142563 |
Kind Code |
A1 |
Hendriks; Bernardus Hendrikus
Wilhelmus ; et al. |
May 22, 2014 |
ENERGY APPLICATION PLANNING APPARATUS
Abstract
The invention relates to an energy application planning
apparatus for planning an application of energy to an object (3)
like a tumor. An energy application element representation
represents an energy application element (5) like an ablation
needle including an energy application part for applying energy and
a sensing part (7). An arrangement of the energy application
element (5) with respect to the object (3) is determined depending
on the positions of the energy application part and the sensing
part (7) with respect to the energy application element (5) as
defined by the energy application element representation and
depending on the object representation. The application of energy
can therefore not only be planned such that the application of
energy is performed as desired, but also such that the object
and/or a surrounding of the object are sensible as desired. In this
way, the planning procedure can be improved.
Inventors: |
Hendriks; Bernardus Hendrikus
Wilhelmus; (Eindhoven, NL) ; Noordhoek; Nicolaas
Jan; (Best, NL) ; Lucassen; Gerhardus Wilhelmus;
(Eindhoven, NL) ; Mielekamp; Pieter Maria;
(Veldhoven, NL) ; Nachabe; Rami; (Eindhoven,
NL) ; Van Der Voort; Marjolein; (Valkenswaard,
NL) ; Bierhoff; Waltherus Cornelis Jozef; (Veldhoven,
NL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Hendriks; Bernardus Hendrikus Wilhelmus
Noordhoek; Nicolaas Jan
Lucassen; Gerhardus Wilhelmus
Mielekamp; Pieter Maria
Nachabe; Rami
Van Der Voort; Marjolein
Bierhoff; Waltherus Cornelis Jozef |
Eindhoven
Best
Eindhoven
Veldhoven
Eindhoven
Valkenswaard
Veldhoven |
|
NL
NL
NL
NL
NL
NL
NL |
|
|
Assignee: |
KONINKLIJKE PHILIPS N.V.
EINDHOVEN
NL
|
Family ID: |
46727268 |
Appl. No.: |
14/131518 |
Filed: |
July 5, 2012 |
PCT Filed: |
July 5, 2012 |
PCT NO: |
PCT/IB2012/053427 |
371 Date: |
January 8, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61506328 |
Jul 11, 2011 |
|
|
|
Current U.S.
Class: |
606/33 ;
264/406 |
Current CPC
Class: |
A61B 5/4244 20130101;
A61B 2034/101 20160201; A61B 5/4839 20130101; A61B 5/0075 20130101;
A61B 5/6852 20130101; A61B 18/14 20130101; A61B 2503/00 20130101;
A61B 2018/00577 20130101; A61B 2017/00057 20130101; A61B 34/10
20160201; A61B 2560/063 20130101 |
Class at
Publication: |
606/33 ;
264/406 |
International
Class: |
A61B 19/00 20060101
A61B019/00; A61B 18/14 20060101 A61B018/14 |
Claims
1. An energy application planning apparatus for planning an
application of energy to an object, the energy application planning
apparatus (1) comprising: an object providing unit (2) for
providing an object representation of the object (3), characterized
in that the energy application planning apparatus further
comprises: an energy application element providing unit (4) for
providing an energy application element representation representing
an energy application element (5) including an energy application
part (6) for applying energy to the object (3) and a sensing part
(7) for generating an optical sensing signal being indicative of a
property of at least one of the object (3) and the surrounding of
the object (3), an arrangement determination unit (9) for
determining an arrangement of the energy application element (5)
with respect to the object (3) depending on the positions of the
energy application part and the sensing part with respect to the
energy application element as defined by the energy application
element representation and depending on the object representation,
wherein the arrangement determination unit (9) is adapted to
determine the position and the orientation of the energy
application element (5) with respect to the object (3) as the
arrangement.
2. (canceled)
3. The energy application planning apparatus as defined in claim 1,
wherein the energy application planning apparatus (1) comprises an
energy influence assignment providing unit (8) for providing
assignments between expected energy influence zones, which define
an expected shape and an expected size of a zone of the object
being influenced by the application of energy, and further energy
application parameters, wherein the arrangement determination unit
(9) is adapted to determine the position of the energy application
element by determining the position of the energy application part
and a further energy application parameter depending on the object
representation and the provided assignments.
4. The energy application planning apparatus as defined in claim 3,
wherein the arrangement determination unit (9) is adapted to
determine the position of the energy application element by
determining a position of the energy application part and by
determining a further energy application parameter such that the
object representation is completely covered by the energy influence
zone defined by the provided assignments, the position of the
energy application part and the further energy application
parameter.
5. The energy application planning apparatus as defined in claim 1,
wherein the arrangement determination unit (9) is adapted to
determine the orientation of the energy application element such
that a provided safety margin surrounding the object representation
is sensible by the sensing part.
6. The energy application planning apparatus as defined in claim 3,
wherein the arrangement determination unit (9) is adapted to
determine several positions of the energy application element by
determining several positions of the energy application part and by
determining several further energy application parameters, which
correspond to the several positions of the energy application part,
and several orientations of the energy application element for the
several positions of the energy application element, such that the
object representation is completely covered by several energy
influence zones defined by the provided assignments, the several
positions of the energy application part and the several further
energy application parameters, and a provided safety margin
surrounding the object representation is sensible by the sensing
part.
7. The energy application planning apparatus as defined in claim 6,
wherein the arrangement determination unit (9) is adapted to
determine a sequence of the several positions and orientations of
the energy application element such that an energy influence zone
generated by applying energy to the object in accordance with a
determined first position, a determined first orientation, and a
determined first energy application parameter, is sensible by the
sensing part, while the energy application element is in a
following determined second position and in a following determined
second orientation.
8. The energy application planning apparatus as defined in claim 1,
wherein the object providing unit (2) is adapted to indicate an
impair region within or adjacent to the object, in which the
application of energy is expected to be impaired, wherein the
arrangement determination unit (9) is adapted to determine the
orientation of the energy application element such that the impair
region is sensible by the sensing part.
9. The energy application planning apparatus as defined in claim 1,
wherein the object providing unit (2) is adapted to indicate a
forbidden region within or around the object, in which the energy
application element is not allowed to be located, wherein the
arrangement determination unit (9) is adapted to determine the
orientation of the energy application element such that the energy
application element is not located within the forbidden region.
10. The energy application apparatus as defined in claim 1, wherein
the energy planning application apparatus (1) comprises a property
determination unit (10) for determining a property of at least one
of the object and the surrounding of the object based on the
generated sensing signal.
11. The energy application apparatus as defined in claim 10,
wherein the energy application planning apparatus (1) is adapted
for planning an ablation procedure and wherein the property
determination unit (10) is adapted to determine whether a sensed
part of at least one of the object and of the surrounding of the
object has been ablated based on the generated sensing signal.
12. The energy application planning apparatus as defined in claim
10, wherein the arrangement determination unit (9) is adapted to
amend the determined arrangement of the energy application element
with respect to the object depending on the object representation
and the determined property of at least one of the object and the
surrounding of the object.
13. An energy application apparatus for applying energy to an
object, the energy application apparatus (11) comprising: an energy
source (16) and an energy application element (5) for applying
energy to the object (3), the energy application element comprising
an energy application part (6) for applying energy to the object
and a sensing part (7) for generating a sensing signal being
indicative of a property of at least one of the object and the
surrounding of the object, an energy application planning apparatus
(1) for planning an application of energy as defined in claim
1.
14. An energy application planning method for planning an
application of energy to an object, the energy application planning
method comprising: providing an object representation of the object
by an object providing unit (2), characterized in that the energy
application planning method further comprises: providing an energy
application element representation representing an energy
application element including an energy application part for
applying energy to the object and a sensing part for generating an
optical sensing signal being indicative of a property of at least
one of the object and the surrounding of the object by an energy
application element providing unit (4), determining an arrangement
of the energy application element with respect to the object
depending on the positions of the energy application part and the
sensing part with respect to the energy application element as
defined by the energy application element representation and
depending on the object representation by an arrangement
determination unit (9), wherein the position and the orientation of
the energy application element (5) with respect to the object (3)
are determined as the arrangement.
15. An energy application planning computer program for planning an
application of energy to an object, wherein the energy application
planning computer program comprising program code means for causing
an energy application planning apparatus as defined in claim 1.
Description
FIELD OF THE INVENTION
[0001] The invention relates to an energy application planning
apparatus, an energy application planning method and an energy
application planning computer program for planning an application
of energy to an object.
BACKGROUND OF THE INVENTION
[0002] US 2011/0015628 A1 discloses an apparatus for planning an
ablation procedure to eliminate a tissue mass in a patient. A
tissue mass is identified in the patient, and an image
representation of an initial planned target volume encompassing the
tissue mass is generated. The initial planned target volume is
inscribed in a template ellipsoidal enclosing ablation volume.
Minor axes of the template ellipsoidal enclosing ablation volume
and the initial planned target volume are scaled upward until they
are equal in magnitude to a major axis of the template ellipsoidal
enclosing ablation volume, to generate an enclosing sphere that
encompasses the scaled planned target volume. In a lookup table a
pre-computed ablation solution having a minimum number of spherical
ablation regions that cover the enclosing sphere is identified, and
a graphical representation of the identified pre-computed ablation
solution overlaid on the sphere is output to a user.
SUMMARY OF THE INVENTION
[0003] It is an object of the present invention to provide an
energy application planning apparatus, an energy application
planning method and an energy application planning computer program
for planning an application of energy to an object, wherein the
planning of the application of energy can be improved.
[0004] In a first aspect of the present invention an energy
application planning apparatus for planning an application of
energy to an object is presented, wherein the energy application
planning apparatus comprises:
[0005] an object providing unit for providing an object
representation of the object,
[0006] an energy application element providing unit for providing
an energy application element representation representing an energy
application element including an energy application part for
applying energy to the object and a sensing part for generating a
sensing signal being indicative of a property of at least one of
the object and the surrounding of the object,
[0007] an arrangement determination unit for determining an
arrangement of the energy application element with respect to the
object depending on the positions of the energy application part
and the sensing part with respect to the energy application element
as defined by the energy application element representation and
depending on the object representation.
[0008] Since the arrangement determination unit is adapted to
determine the arrangement of the energy application element with
respect to the object not only depending on the position of the
energy application part with respect to the energy application
element, but also depending on the position of the sensing part
with respect to the energy application element, the position of the
sensing part with respect to the object can be considered, while
planning the application of energy. This allows planning the
application of energy such that not only the application of energy
is performed as desired, but also such that the object and/or a
surrounding of the object are sensible as desired. In this way, the
planning procedure can be improved.
[0009] The object is preferentially a tumor and the energy
application element is preferentially an ablation needle for
ablating the tumor. In particular, the energy application part can
comprise an ablation electrode surrounded by several sensing parts,
which preferentially comprise optical sensors for optically sensing
a property of at least one of the object and the surrounding of the
object. The ablation electrode is preferentially a radio frequency
(RF) ablation electrode. The sensing parts can be used for
monitoring the development of an ablated region, while the needle
is located within the tumor in the planned arrangement and while
the energy is applied by the ablation electrode.
[0010] The arrangement determination unit can be adapted to
determine one or several arrangements of the energy application
element with respect to the object for applying energy to the
object one or several times.
[0011] The object providing unit can be adapted to segment the
object in a three-dimensional image like a computed tomography
image or a magnetic resonance image for providing the object
representation. The object providing unit can also be a storing
unit in which the object representation, for example, a segmented
tumor, is stored already, or an entire system comprising an imaging
modality for generating a three-dimensional image showing the
object and a segmentation unit for segmenting the object in the
generated three-dimensional image.
[0012] The energy application element providing unit is
preferentially a storing unit in which the energy application
element representation is stored and from which the energy
application element representation can be retrieved for determining
the arrangement of the energy application element with respect to
the object.
[0013] The object is preferentially a tumor and the sensing part is
preferentially adapted to determine whether the respective tumor
region of the object sensed by the respective sensing part has been
ablated or not. In particular, one or several sensing parts are
provided comprising optical sensors for optically sensing the
tissue at the respective sensing part, wherein it can be determined
whether the tissue is ablated or not based on the optical
sensing.
[0014] In a preferred embodiment, the arrangement determination
unit is adapted to determine the position and the orientation of
the energy application element with respect to the object as the
arrangement.
[0015] It is preferred that the energy application planning
apparatus comprises an energy influence assignment providing unit
for providing assignments between expected energy influence zones,
which define an expected shape and an expected size of a zone of
the object being influenced by the application of energy, and
further energy application parameters, wherein the arrangement
determination unit is adapted to determine the position of the
energy application element by determining the position of the
energy application part and a further energy application parameter
depending on the object representation and the provided
assignments. The further energy application parameter is, for
example, the power applied to the energy application part, the time
of applying energy, et cetera.
[0016] The object is preferentially a part of a living being,
wherein the energy application planning apparatus can be adapted to
plan an ablation of tissue of the object by the application of
energy, wherein the energy influence zone is an expected ablation
zone, which defines the expected shape and the expected size of an
ablated zone of the living being.
[0017] It is further preferred that the arrangement determination
unit is adapted to determine the position of the energy application
element by determining a position of the energy application part
and by determining a further energy application parameter such that
the object representation is completely covered by the energy
influence zone defined by the provided assignments, the position of
the energy application part and the further energy application
parameter. This allows determining the position of the energy
application part, in particular, of an ablation RF electrode, such
that the object, for instance, a tumor, is completely ablated.
[0018] It is also preferred that the arrangement determination unit
is adapted to determine the orientation of the energy application
element such that a provided safety margin surrounding the object
representation is sensible by the sensing part. Thus, during
applying the energy to the object and/or after the energy has been
applied to the object, while the energy application element is
arranged in the determined arrangement within the object, it can be
sensed by the sensing part of the energy application element,
whether the influence of the application of energy has reached the
safety margin, whereby it can be concluded whether the object has
been influenced completely, for example, has been ablated
completely, at least between the position of the energy application
part and the part of the safety margin sensed by the sensing part
or not. It can therefore be determined, whether the object has been
completely influenced at least between the energy application part
and the part of the safety margin sensed by the sensing part,
without necessarily sensing the object between the position of the
energy application part and the part of the safety margin sensed by
the sensing part.
[0019] In an embodiment, the arrangement determination unit is
adapted to determine the orientation of the energy application
element also depending on the determined position of the energy
application element. Thus, the orientation of the energy
application element can be determined, while it is assumed that the
position of the energy application part is fixed with respect to
the object as determined by the arrangement determination unit.
[0020] In a preferred embodiment the arrangement determination unit
is adapted to determine
[0021] several positions of the energy application element by
determining several positions of the energy application part and by
determining several further energy application parameters, which
correspond to the several positions of the energy application part,
and
[0022] several orientations of the energy application element for
the several positions of the energy application element, such
that
[0023] the object representation is completely covered by several
energy influence zones defined by the provided assignments, the
several positions of the energy application part and the several
further energy application parameters, and
[0024] a provided safety margin surrounding the object
representation is sensible by the sensing part. The several
orientations of the energy application element can be determined
such that the safety margin is sensible as homogenously as
possible. This further improves the planning of the application of
energy such that the object, which can be a tumor, is completely
influenced by the energy, in particular, completely ablated,
wherein at the same time the application of the energy can be
reliably monitored by sensing the safety margin surrounding the
object.
[0025] It is further preferred that the arrangement determination
unit is adapted to determine a sequence of the several positions
and orientations of the energy application element such that an
energy influence zone generated by applying energy to the object in
accordance with a determined first position, a determined first
orientation, and a determined first energy application parameter,
is sensible by the sensing part, while the energy application
element is in a following determined second position and in a
following determined second orientation. This allows assessing the
result of applying energy to the object in accordance with a
planned first position, a planned first orientation and a planned
first energy application parameter by using the sensing part, while
the energy application element is in the following planned second
position and in the following planned second orientation. This
allows the user to immediately react to the result of the
application of energy in accordance with the first planned
position, orientation and further energy application parameter. For
example, if an undesired result is sensed, the second position,
orientation and further energy application parameter and optionally
further following positions, orientations and energy application
parameters can consider this undesired result.
[0026] In a preferred embodiment, the object providing unit is
adapted to indicate an impair region within or adjacent to the
object, in which the application of energy is expected to be
impaired, wherein the arrangement determination unit is adapted to
determine the orientation of the energy application element such
that the impair region is sensible by the sensing part. If the
object is a part of a living being like a tumor, which should be
ablated, the impair region can be a region close to a blood vessel,
which may influence the application of energy due to heat drainage.
The orientation of the sensing part is preferentially determined
such that an impair region within a safety margin surrounding the
object is sensible by the sensing part. The impair regions are
regions, which are known to, for example, not behave as expected in
accordance with an expected ablation zone. By arranging the energy
application element that these impair regions are sensed, the
influence of the energy can be sensed at these problematic regions
and the planning of the energy application can consider the result
of the sensing at these problematic regions, thereby allowing the
energy application planning apparatus to further improve the
quality of planning the application of energy.
[0027] It is preferred that the object providing unit is adapted to
indicate a forbidden region within or around the object, in which
the energy application element is not allowed to be located,
wherein the arrangement determination unit is adapted to determine
the orientation of the energy application element such that the
energy application element is not located within the forbidden
region. If the object is a part of a living being like a person or
an animal, the forbidden region can be a bone region or a vessel
region, which should not be damaged by the energy application
element. This consideration of the forbidden region, while planning
the application of energy, can further improve the quality of
planning the application of energy.
[0028] It is further preferred that the energy planning application
apparatus comprises a property determination unit for determining a
property of at least one of the object and the surrounding of the
object based on the generated sensing signal. If the energy
application planning apparatus is adapted for planning an ablation
procedure, the property determination unit is preferentially
adapted to determine whether a sensed part of at least one of the
object and of the surrounding of the object has been ablated based
on the generated sensing signal.
[0029] In a preferred embodiment, the arrangement determination
unit is adapted to amend the determined arrangement of the energy
application element with respect to the object depending on the
object representation and the determined property of at least one
of the object and the surrounding of the object. Since the
application of energy can be adapted to the already measured
property of the object, in particular, based on whether regions of
the object, which are expected to have been influenced by the
energy already, are really already influenced by the application of
energy, the planning of the application of energy can be further
improved.
[0030] In a further aspect of the present invention an energy
application apparatus for applying energy to an object is
presented, wherein the energy application apparatus comprises:
[0031] an energy application element for applying energy to the
object, the energy application element comprising an energy
application part for applying energy to the object and a sensing
part for generating a sensing signal being indicative of a property
of at least one of the object and the surrounding of the
object,
[0032] an energy application planning apparatus for planning an
application of energy as defined in claim 1.
[0033] The energy application apparatus allows therefore a user to
or allows to automatically apply energy to the object in accordance
with the energy application plan determined by the energy
application planning apparatus. For example, the planned
arrangement of the energy application element can be shown to the
user on a display and the user can then arrange the energy
application element in accordance with the determined planned
arrangement. Alternatively, the energy application apparatus can
comprise a steering unit for introducing the energy application
element automatically into the object in the planned
arrangement.
[0034] The energy application apparatus can comprise one or several
energy application elements, in particular, one or several ablation
needles. If the energy application apparatus comprises several
energy application elements, energy can be applied and/or the
object can be sensed at different positions simultaneously.
[0035] The sensing part can comprise an optical sensor for
generating an optical sensing signal being indicative of the
property of at least one of the object and the surrounding of the
object. For example, at least one of the object and the surrounding
of the object can be illuminated by light, wherein absorbed and
scattered light can be collected by the optical sensor for
generating the optical sensing signal. The optical sensing signal,
which is indicative of the absorption and the scattering of the
light, can be used by the property determination unit for
determining the property of at least one of the object and the
surrounding of the object, for example, for determining whether
tissue has already been ablated.
[0036] The energy application element can comprise a further
sensing part comprising a non-optical sensor. For example, the
further sensing part can comprise a temperature sensor and/or a
pressure sensor. The further sensing part can provide further
information, which can be used for monitoring the application of
energy to the object.
[0037] In a further aspect of the present invention an energy
application planning method for planning an application of energy
to an object is presented, wherein the energy application planning
method comprises:
[0038] providing an object representation of the object by an
object providing unit,
[0039] providing an energy application element representation
representing an energy application element including an energy
application part for applying energy to the object and a sensing
part for generating a sensing signal being indicative of a property
of at least one of the object and the surrounding of the object by
an energy application element providing unit,
[0040] determining an arrangement of the energy application element
with respect to the object depending on the positions of the energy
application part and the sensing part with respect to the energy
application element as defined by the energy application element
representation and depending on the object representation by an
arrangement determination unit.
[0041] In a further aspect of the present invention an energy
application planning computer program for planning an application
of energy to an object is presented, wherein the energy application
planning computer program comprises program code means for causing
an energy application planning apparatus as defined in claim 1 to
carry out the steps of the energy application planning method as
defined in claim 14, when the energy application computer program
is run on a computer controlling the energy application
apparatus.
[0042] It shall be understood that the energy application planning
apparatus of claim 1, the energy application apparatus of claim 13,
the energy application planning method of claim 14 and the energy
application planning computer program of claim 15 have similar
and/or identical preferred embodiments, in particular, as defined
in the dependent claims.
[0043] It shall be understood that a preferred embodiment of the
invention can also be any combination of the dependent claims with
the respective independent claim.
[0044] These and other aspects of the invention will be apparent
from and elucidated with reference to the embodiments described
hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] In the following drawings:
[0046] FIG. 1 shows schematically and exemplarily an embodiment of
an energy application planning apparatus for planning an
application of energy to an object,
[0047] FIG. 2 shows schematically and exemplarily an embodiment of
an ablation needle,
[0048] FIG. 3 shows a flowchart exemplarily illustrating an
embodiment of an energy application planning method for planning an
application of energy to an object,
[0049] FIG. 4 shows a flowchart exemplarily illustrating an
embodiment of an energy application method for applying energy to
an object,
[0050] FIG. 5 shows schematically and exemplarily a tip of a
further embodiment of an ablation needle,
[0051] FIG. 6 shows schematically and exemplarily several
arrangements of an ablation needle within an object,
[0052] FIG. 7 shows exemplarily a reflectance spectrum of normal
liver tissue,
[0053] FIG. 8 shows exemplarily a reflectance spectrum of tumor
liver tissue,
[0054] FIG. 9 shows exemplarily a reflectance spectrum of ablated
liver tissue, and
[0055] FIG. 10 shows exemplarily absorption spectra of oxygenated
hemoglobin, hemoglobin, water and fat.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0056] FIG. 1 shows schematically and exemplarily an embodiment of
an energy application apparatus for applying energy to an object.
The energy application apparatus 11 is an ablation apparatus for
applying an ablation procedure to the object. The object is, in
this embodiment, a tumor within a person 12 located on a table 13.
The energy application apparatus 11 comprises an energy application
element 5 for applying energy to the object. An embodiment of the
energy application element 5 is schematically and exemplarily shown
in more detail in FIG. 2.
[0057] The energy application element 5 is, in this embodiment, an
ablation needle comprising an energy application part 6 for
applying energy to the object and several sensing parts 7 for
generating a sensing signal being indicative of a property of at
least one of the object and the surrounding of the object. The
energy application part 6 is surrounded by an equal number of
sensing parts 7 on each side of the energy application part 6 on
the energy application element 5. In this embodiment, three sensing
parts 7 are provided on each side of the energy application part 6
on the ablation needle 5. In other embodiments, more or less
sensing parts 7 can be provided on the energy application element
5.
[0058] In this embodiment, the sensing parts 7 comprise optical
sensors for generating an optical sensing signal being indicative
of a property of at least one of the object and the surrounding of
the object. In particular, the optical sensors can comprise one or
several optical fibers for emitting light, which is directed to the
object, and one or several optical fibers for detecting light from
the object for generating the optical signal. The optical sensing
signal is preferentially indicative of the absorption and/or the
scattering of the light and can be used for determining the
property of at least one of the object and the surrounding of the
object, for example, for determining whether tissue has already
been ablated or not. The energy application part 6 preferentially
comprises an ablation electrode being an RF ablation electrode. The
sensing part 7 can be used for monitoring the development of an
ablated region, while the ablation needle 5 is located within the
tumor and while the ablation energy is applied by the ablation
electrode.
[0059] The ablation needle 5 is connected to an ablation needle
control unit 15 via a connection element 14 like a cable. The
ablation needle control unit 15 comprises an electrical energy
source 16, in particular, an RF source, for applying energy, in
particular, RF energy to the object, via electrical connections
within the connection element 14 and the ablation electrode. The
ablation needle control unit 15 further comprises a light source
17, which provides light, which is guided to the sensing parts 7 of
the ablation needle 5 by using one or several optical fibers, and a
light detection unit 18 for detecting light, which has been altered
by absorbance and/or scattering by the object, collected by one or
several optical fibers and transferred to the light detection unit
18 by the one or several optical fibers. The ablation needle 5 can
be guided and arranged by a user like a physician or radiologist
under image guidance as will be described in the following.
[0060] During the guidance of the ablation needle 5 to the object
and during the arranging procedure for arranging the ablation
needle within the object in a desired position and in a desired
orientation, a fluoroscopy device 21 images the ablation needle 5
within the person 12. The fluoroscopy device 21 comprises an X-ray
source 22, which generates an X-ray beam 23 for traversing a region
of the person 12, in which the ablation needle 5 is present. After
the X-ray beam 23 has traversed the person 12, the X-ray beam 23 is
detected by an X-ray detector 24. The X-ray source 22 and the X-ray
detector 24 are controlled by a fluoroscopy control unit 25, which
generates a fluoroscopy image based on the detected X-ray beam
23.
[0061] The energy application apparatus 11 further comprises an
energy application planning apparatus 1 for planning the
application of energy to the object. The energy application
planning apparatus 1 comprises an object providing unit 2 for
providing an object representation of the object, i.e., in this
embodiment, a representation of a tumor to be ablated. The energy
application planning apparatus 1 further comprises an energy
application element providing unit 4 for providing an energy
application element representation representing the energy
application element 5, i.e., in this embodiment, the ablation
needle 5, and an arrangement determination unit 9 for determining
an arrangement of the energy application element 5 with respect to
the object depending on the positions of the energy application
part 6 and the sensing parts 7 with respect to the energy
application element 5 as defined by the energy application element
representation and depending on the object representation. In this
embodiment, the arrangement determination unit 9 is adapted to
determine several arrangements of the energy application element 5
with respect to the object for applying energy to the object
several times.
[0062] The object providing unit 2 can be adapted to segment the
object in a provided three-dimensional image of the person 12,
which includes the object, like a computed tomography image or a
magnetic resonance image for providing the object representation.
Thus, the object representation is preferentially a
three-dimensional segmented tumor. The object providing unit can
also be a storing unit, in which the object representation, which
has been determined already by another unit, is stored, or the
object providing unit can also be an entire system comprising an
imaging modality for generating a three-dimensional image showing
the person 12 and the object with the person 12 and a segmentation
unit for segmenting the object in the generated three-dimensional
image.
[0063] The energy application element providing unit 4 is
preferentially a storing unit, in which the energy application
element representation is stored and from which the energy
application element representation can be retrieved for determining
the arrangement of the energy application element 5 with respect to
the object. The energy application element providing unit 4
includes preferentially a model of the energy application element
defining the positions of the energy application part and the
sensing parts with respect to the energy application element 5,
wherein the model is the energy application element
representation.
[0064] The energy application planning apparatus 1 further
comprises an energy influence assignment providing unit 8 for
providing assignments between expected energy influence zones,
which define an expected shape and an expected size of a zone of
the object being influenced by the application of energy, and
further energy application parameters. In this embodiment, the
energy influence assignment providing unit 8 is adapted to provide
assignments between expected ablation zones, which define the
expected shape and the expected size of an ablated zone of the
person 12, wherein within the ablated zone the tissue has been
ablated, and further energy application parameters like the power
of applying the RF energy, the time of applying the RF energy, et
cetera.
[0065] The arrangement determination unit 9 can be adapted to
determine the position of the energy application element 5 by
determining the position of the energy application part 6 and a
further energy application parameter depending on the object
representation and the provided assignments. In particular, the
arrangement determination unit 9 can be adapted to determine the
position of the energy application element 5 by determining a
position of the energy application part 6 and by determining a
further energy application parameter such that the object
representation is completely covered by the energy influence zone
defined by the provided assignments, the position of the energy
application part 6 and the further energy application
parameter.
[0066] The arrangement determination unit 9 can be further adapted
to determine the orientation of the energy application element 5
such that a provided safety margin surrounding the object
representation is sensible by at least one of the sensing parts 7.
The arrangement determination unit 9 can therefore not only
determine the position of the energy application part 6 within the
object, i.e., in this embodiment, within the tumor, but also the
orientation of the energy application element 5 within the object
as the arrangement of the energy application element 5. In
particular, the arrangement determination unit 9 is preferentially
adapted to determine several positions of the energy application
element 5 by determining several positions of the energy
application part 6 and by determining several further energy
application parameters, which correspond to the several positions
of the energy application part 6, and to determine several
orientations of the energy application element 5 for the several
positions of the energy application element 5 such that the object
representation is completely covered by several energy influence
zones defined by the provided assignments, the several positions of
the energy application part 6 and the several further energy
application parameters, and such that the provided safety margin
surrounding the object representation is sensible by the sensing
parts 7. In an embodiment, these arrangements of the energy
application element 5 can be determined such that the safety margin
is sensible as homogeneously as possible. Alternatively or in
addition, the several orientations of the energy application
element 5 can also be determined depending on other criteria.
[0067] For instance, the object providing unit 2 can be adapted to
indicate an impair region within or adjacent to the object, in
which the application of energy is expected to be impaired, wherein
the arrangement determination unit 9 can be adapted to determine
the orientation of the energy application element 5 such that the
impair region is sensible by at least one of the sensing parts 7.
The impair region can be a region close to a blood vessel, which
may influence the application of energy due to heat drainage. A
region close to a blood vessel can be determined, for example, by
segmenting a blood vessel in a provided three-dimensional image of
the person 12 including the object and the surrounding of the
object. The same three-dimensional image may be used for
determining the object representation, i.e., in this embodiment,
the segmented tumor, and the impair region. The object providing
unit can be adapted to indicate one or several impair regions,
wherein the arrangement determination unit 9 can be adapted to
orient the ablation needle 5 such that the one or several impair
regions are sensible by the sensing parts 7. In an embodiment, the
arrangement determination unit 9 is adapted to determine the
orientations of the ablation needle 5 such that at least one or
several impair regions within the provided safety margin are
sensible by the sensing parts 7.
[0068] A further criterion, which may be used by the arrangement
determination unit 9 for determining the orientation of the energy
application element 5 can be a forbidden region within or around
the object, in which the energy application element 5 is not
allowed to be located. The object providing unit 2 can be adapted
to indicate this forbidden region and the arrangement determination
unit 9 can be adapted to determine the orientation of the energy
application element 5 such that the energy application element 5 is
not located within the forbidden region. The person 12 comprises
regions, through which the ablation needle 5 cannot be navigated
and in which the ablation needle 5 cannot be located. Such
forbidden regions are defined, for example, by a bone region or a
vessel region within the person 12, which should not be damaged by
the ablation needle 5.
[0069] A further criterion, which can be used for determining the
orientations of the energy application element 5, can be orienting
the energy application element 5 such that an energy influence zone
generated by applying energy to the object in accordance with a
determined previous position, a determined previous orientation,
and a determined previous energy application parameter, is sensible
by the sensing parts 7, while the energy application element 5 is
in a determined current position and a determined current
orientation. Thus, a sequence of several positions and orientations
of the energy application element 5 can be determined such that the
sensing parts 7 in a current arrangement of the energy application
element 5 can sense the energy influence zone generated, while the
energy application element was arranged in a previous arrangement,
in particular, in an immediately previous arrangement.
[0070] The energy planning application apparatus 1 further
comprises a property determination unit 10 for determining a
property of at least one of the object and the surrounding of the
object based on the generated sensing signal. In particular, the
property determination unit 10 is adapted to determine, whether a
sensed part of at least one of the object and of the surrounding of
the object has been ablated based on the generated sensing signal.
This information regarding already ablated tissue can be used to
amend already planned arrangements of the energy application
element 5. For example, the object representation without the
already ablated regions define a region to be ablated, wherein the
arrangement determination unit 9 can be adapted to amend the
following already planned arrangements of the energy application
element by determining the positions of the energy application
element for the following applications of energy such that the
corresponding energy influence zones completely cover the region to
be ablated.
[0071] The arrangement determination unit 9 can therefore be
adapted to determine the positions of the energy application
element 5 such that the object representation and/or the region to
be ablated, which is defined by the object representation and
already ablated regions, are completely covered by the energy
influence zones and to determine the orientations of the energy
application element 5 such that the safety margin, in particular,
the safety margin in an impair region, is sensible by the sensing
parts 7 and optionally further such that the energy application
element is not located and navigated through a forbidden region
and/or the sensing parts 7 can sense the result of a previous
application of energy performed while the energy application
element 5 was in previous arrangement.
[0072] The energy application apparatus 11 further comprises an
apparatus control unit 26 for controlling the energy application
planning apparatus 1, the ablation needle control unit 15 and the
fluoroscopy device 21, and a display 20 for displaying, for
example, a fluoroscopy image generated by the fluoroscopy device
21, an object representation, for example, a segmented
three-dimensional tumor, an energy application element
representation, et cetera.
[0073] In the following, an embodiment of an energy application
planning method for planning an application of energy to an object
will exemplarily be described with reference to a flowchart shown
in FIG. 3.
[0074] In step 101, an object representation is provided by the
object providing unit 2. In particular, a tumor is segmented in a
three-dimensional image of the person 12, which comprises the
tumor, and the segmented three-dimensional tumor is provided as the
object representation. In step 102, an energy application element
representation, which represents the energy application element 5
including the energy application part 6 and the sensing parts 7, is
provided by the energy application element providing unit 4. In
particular, a model of the ablation needle is provided, which
defines the positions of the energy application part 6 and the
sensing parts 7 on the ablation needle 5. In step 103, an
arrangement of the energy application element 5 with respect to the
object is determined depending on the positions of the energy
application part 6 and the sensing parts 7 with respect to the
energy application element 5 as defined by the energy application
element representation and depending on the object representation
by the arrangement determination unit 9. Preferentially, the
arrangement determination unit 9 determines several positions of
the energy application element 5 by determining several positions
of the energy application part 6 and by determining several further
energy application parameters like the power and the time of
applying the energy, which correspond to the several positions of
the energy application part 6, and several orientations of the
energy application element 5 for the several positions of the
energy application element 5 such that the object representation is
completely covered by several energy influence zones defined by the
provided assignments, the several positions of the energy
application part 6 and the several further energy application
parameters, and such that the provided safety margin surrounding
the object representation is sensible by at least one of the
sensing parts 7.
[0075] In the following, an embodiment of an energy application
method for applying energy to an object will exemplarily be
described with reference to a flowchart shown in FIG. 4.
[0076] In step 201, the application of energy is planned in
accordance with the above described energy application planning
method. In this embodiment, in step 201, several arrangements for
arranging the energy application element 5 within the object are
determined. In step 202, the energy application element 5 is
arranged within the object in accordance with one of the determined
several arrangements, and, in step 203, energy is applied to the
object via the energy application part 6. Moreover, in step 203,
the object and the surrounding of the object are monitored by using
the sensing parts 7. In step 204, a property of at least one of the
object and the surrounding of the object is determined based on
sensing signals generated by the sensing parts 7 of the energy
application element 5. In this embodiment, it is determined,
whether the parts of at least one of the object and the surrounding
of the object, which have been sensed by the sensing parts 7, have
been ablated or not. In step 205, it is determined, whether the
determined ablated regions correspond to an expected ablation zone,
which was expected having regard to the position of the energy
application part with respect to the object and having regard to
the used energy application parameters like the used power settings
and the time of applying energy to the object. If the determined
ablated regions and the expected ablation zone are similar and if
energy has not been applied in all arrangements of the energy
application element 5 determined in step 201, the energy
application method continues with step 202. If the determined
ablated regions deviate from the expected ablation zone, the
already planned arrangements of the energy application element 5
are modified by planning these arrangements again under
consideration of the determined already ablated regions. Thus, the
method continues with step 201, in which a re-planning of the
following arrangements is performed. If the determined ablated
regions indicate that the object has been ablated completely, the
energy application method ends in step 206.
[0077] In the field of oncology various tumors are treated with an
ablation needle. Since the area that can be treated at one location
of the ablation needle is limited, for larger sized tumors multiple
ablations with different needle positions are required. In
particular, planning of this ablation needle positioning is
required for a good treatment of the tumor. Apart from planning,
feedback on the ablation areas created at the different needle
positions is helpful, because these areas can strongly depend on
the tissue structure, i.e., for instance a blood vessel can act as
a local heat sink and can reduce the size of the created ablation
area. The energy application planning apparatus allows providing a
feedback on the lesion growth, i.e., on the growth of the ablation
zone, along the ablation needle direction and/or feedback on
three-dimensional volume growth based on the sensed regions of at
least one of the tumor and of the surrounding of the tumor sensed,
while the ablation needle is located in different orientations. The
energy application planning apparatus is adapted to not only plan
the needle position by planning the position of the energy
application part of the ablation needle, but to determine also the
orientation of the ablation needle in such a way that the sensing
part positions for the different ablation needle positions for the
ablations sample the volume of the tumor ablation area in a
representative way. The measurement information of these sensor
part positions can be feedback to the planning algorithm. Depending
on this feedback the treatment can be evaluated as being
successful, and, if not successful, an additional ablation needle
location can be planned, in order to ablate the tumor completely.
The measurement information can be stored in the above mentioned
three-dimensional image of the tumor and of the surrounding of the
tumor, which has preferentially been used for segmenting the tumor,
wherein the three-dimensional image with the stored measured
optical feedback information can be shown in the display 20. For
example, identified ablated and non-ablated regions can be colored
differently on the display 20.
[0078] The energy application planning apparatus and the energy
application apparatus can provide the advantage that, without
additional needle insertion than those already needed for an
ablation procedure, a representative inspection of the ablation
zone can be obtained. Only a single ablation needle can be used,
which is preferentially arranged several times in several positions
and/or orientations for applying the ablation energy several times
in different arrangements, or several ablation needles may be used
during the ablation procedure so that the sensing parts of the
several ablation needles can sense the tumor and/or the surrounding
of the tumor at the same time. For example, two ablation needles
can be arranged within the tumor such that the sensing parts of the
two ablation needles can simultaneously sense the tumor and/or the
surrounding of the tumor. The sensing parts preferentially comprise
optical sensors. The ablation needle can further be equipped with
other sensors, which are preferentially not located in the sensing
parts, in which the optical sensors are located. These other
sensors provide further information, which can be used for, for
example, monitoring the growth of the ablation zone. These other
sensors are, for instance, temperature sensors, pressure sensors,
et cetera.
[0079] FIG. 5 shows schematically and exemplarily a tip of a
further embodiment of an ablation needle. The tip of the ablation
needle 27 comprises optical fibers 28 and an irrigation hole 29.
The end 30 of the tip of the ablation needle 27 comprises a
metallic ablation electrode, which is separated from the further
parts of the ablation needle 27 by an insulating bush 31. Within
the tip of the ablation needle 27, in particular, within the
metallic end 30 of the ablation needle 27, a temperature sensor
like a thermal-couple can be situated for providing further
information, which can be used, for instance, for monitoring the
temperature during the ablation procedure and for providing the
monitored temperature as a feedback to a user and/or to a
controller for controlling the application of energy, in order to
allow the user and/or the controller to apply the energy depending
on the monitored temperature.
[0080] The optical fibers 28 form an optical sensor, wherein one or
two of the optical fibers can emit light, which is absorbed and/or
scattered by the tissue and wherein the other one or two optical
fibers can collect the light being altered by absorbance and/or
scattering by the tissue. The ablation needle 27 shown in FIG. 5
can comprise further sensing parts and/or energy application parts
distributed along the ablation needle 27. Moreover, also the
ablation needle 5 described above with reference to FIG. 2 can
comprise a tip as shown in FIG. 5.
[0081] By using different needle positions and orientations, it is
possible to probe the area around the tumor at different locations
in the three-dimensional space allowing a representative probing of
the ablation volume. Preferentially, the geometry of the tumor is
known from a three-dimensional segmentation of the tumor in a
provided three-dimensional image. The locations of the sensing
part, in particular, of the RF ablation electrode, of the ablation
needle can then be determined, wherein then the allowed angles of
the ablation needle, i.e., possible orientations of the ablation
needle, can be determined such that no vital structures like bones,
vessels, et cetera are hit. From these possible angles, i.e., from
these possible orientations, the angles of the ablation needle can
be determined such that an optimal probing of the ablation zone is
possible. Moreover, the order of the different arrangements, in
which the ablation needle may be arranged, can be determined such
that an ablated part of the tumor, which has been ablated, while
the ablation needle was in a first orientation at a first location,
can be probed, while the ablation needle is in a following second
orientation at a following second position.
[0082] FIG. 6 shows schematically and exemplarily three different
arrangements of the ablation needle 5 within a tumor 3. The energy
application part of the ablation needle 5 is within the tumor 3. In
each arrangement of the ablation needle 5, two sensing parts 7 of
the ablation needle 5 are located outside of the tumor 3 within a
safety margin surrounding the tumor 3. The sensing parts 7 can
therefore be used to determine whether the ablation zone has
reached the safety margin.
[0083] The light source 17 can be a broadband light source like,
for example, a tungsten halogen broadband lamp, or a laser, wherein
the wavelength of the laser can be swept from, for example, 500 to
1600 nm. The sweeping can be performed by directly modifying the
laser wavelength and/or by using, for example, an optical
grating.
[0084] The light is transmitted to the sensing parts by using at
least one optical fiber, wherein the transmitted light is emitted
to the tissue, which absorbs and/or scatters the light, the light
being altered by absorbance and/or scattering by the tissue is
collected by at least one further optical fiber of the respective
sensing part, and the collected light is transmitted to the light
detection unit 18. The distal ends of an emitting fiber and of a
collecting fiber are preferentially spatially separated by a
distance of 1 to 3 mm, further preferred by a distance of 1 to 2
mm.
[0085] The intensity of the collected light is determined by the
absorption and scattering properties of the object and/or of the
surrounding of the object and can therefore be used for determining
a property of the object and/or of the surrounding of the object.
For example, it can be determined, whether the object and/or the
surrounding of the object has been ablated or not. Upon spatial and
temporal multiplexing, scattered and/or absorbed light can be
collected at multiple sites of the ablation needle. Also a
wavelength-dependent multiplexing can be performed.
[0086] FIGS. 7 to 9 show exemplarily the measured spectra of
different kinds of tissue. FIG. 7 shows a spectrum of normal liver
tissue, FIG. 8 shows a spectrum of tumor liver tissue and FIG. 9
shows a spectrum of ablated liver tissue. As can be seen, these
spectra are very different such that they can be used for
distinguishing between normal liver tissue, tumor liver tissue and
ablated liver tissue based on the collected absorbed and/or
scattered light. FIGS. 7 to 9 show the intensity in arbitrary units
depending on the wavelength in nm.
[0087] There are various ways to quantify the difference between
the measured spectra as observed in FIGS. 7 to 9. For example, the
property determination unit 10 can be adapted to compare an
actually measured spectrum with known spectra of respective ablated
tissue and respective non-ablated tissue and to determine whether
the respective sensed part of the object is ablated or not based on
the comparison. For the comparison a similarity measure like the
sum of squared differences or a correlation of the spectra can be
used.
[0088] In an embodiment, optical tissue properties such as the
scattering coefficient and the absorption coefficient of different
tissue chromophores like hemoglobin, oxygenated hemoglobin, water,
fat, et cetera are employed to quantify the difference between the
spectra measured on non-ablated and ablated tissue. The chromophore
concentrations can be determined by spectral fitting as described
in the article "Estimation of lipid and water concentrations in
scattering media with diffuse optical spectroscopy from 900 to 1600
nm" by Rami Nachabe et al., Journal of Biomedical Optics, 15 (3),
2010, which is herewith incorporated by reference, i.e. the
spectral fitting disclosed in this article cannot only be applied
to fat and water, but also to other elements like hemoglobin and
oxygenated hemoglobin. The main absorbing constituents in normal
tissue dominating the absorption in the visible and near-infrared
range are blood (i.e. hemoglobin), water and fat. In FIG. 10 the
absorption coefficients of these chromophores as a function of the
wavelength are presented. In FIG. 10, the curve 35 denotes
oxygenated hemoglobin, the curve 32 denotes hemoglobin, the curve
33 denotes water and the curve 34 denotes fat. Note that blood
dominates the absorption in the visible range, while water and fat
dominate in the near infrared range. These optical tissue
properties change during tissue ablation and are significantly
different for non-ablated tissue compared with ablated tissue.
Furthermore, based on these properties different types of tissue,
in particular, healthy muscle tissue, can be discriminated from
already ablated tissue or from fat tissue.
[0089] The total absorption coefficient is a linear combination of
the absorption coefficients of, for instance, blood, water and fat
(hence for each component the value of that shown in FIG. 10
multiplied by its volume fraction). Correspondingly, the scattering
coefficient can be expressed as a power law of the wavelength. By
using the spectral fitting described in the above mentioned article
by Nachabeet al. the volume fractions of the blood, water and fat
as well as the scattering coefficients can be determined. With this
method the measured spectra can be translated in physiological
parameters that can be used to discriminate different tissues. In,
for instance, the article by Nachabe et al. "Effect of bile
absorption coefficients on the estimation of liver tissue optical
properties and related complications in discriminating healthy and
tumours samples", Biomedical Optics Express, vol. 2, pages 600 to
614 (2011), which is herewith incorporated by reference, the above
method is used to discriminate, for example, healthy liver tissue
from tumor liver tissue.
[0090] Employing this method to the measured spectra shown in FIGS.
7 to 9 reveals that the water content as well the scattering
increases in ablated tissue compared to non-ablated tissue.
Furthermore, in this example the blood content in normal liver
tissue is significantly higher than in tumor tissue. The property
determination unit 10 can be adapted to determine whether tissue is
ablated or non-ablated based on the above described spectral
fitting procedure. For example, the property determination unit 10
can be adapted to determine the water content, the scattering
coefficient, and the blood content by using the spectral fitting
procedure, and to determine whether the tissue is ablated or
non-ablated by comparing these measured tissue properties with
corresponding stored tissue properties being indicative of ablated
and non-ablated tissue.
[0091] Another way to discriminate differences in spectra is by
making use of a principal components analysis. This method allows
classification of differences in spectra and thus allows
discrimination between tissues. It is also possible to extract
features from certain parts of the spectra and use these to
discriminate the various spectra. Moreover, changes in the water
absorption spectra as a function of temperature can be used to
determine the temperature of the tissue surrounding the needle.
[0092] Although diffuse reflectance spectroscopy is described above
to extract tissue properties, also other optical methods can be
used for determining a property of the object and/or of the
surrounding of the object. For example, a fluorescence measurement,
diffuse optical tomography by employing a plurality of optical
fibers, differential pass length spectroscopy and/or Raman
spectroscopy can be used for determining a property of the object
and/or of the surrounding of the object.
[0093] The energy application planning apparatus and the energy
application apparatus are preferentially adapted to be used in the
field of oncology, in particular, for the planning of RF ablation
treatments of tumors. However, the energy application apparatus and
the energy application planning apparatus can also be used for
ablating other objects like heart tissue for treating heart rhythm
problems.
[0094] Although in the above described embodiments the sensing part
of the energy application element comprises an optical sensor, in
other embodiments the sensing part can also be adapted to use other
techniques for sensing the object and/or the surrounding of the
object. For instance, the object and/or the surrounding of the
object can be sensed by using ultrasound or can be electrically
sensed.
[0095] Although in the above described embodiments an ablation
needle has been used for applying energy to the object, also other
devices can be used for applying energy like a tip of an ablation
catheter comprising an energy application element and at least one
sensing element, wherein, in this case, the catheter tip does not
comprise an ablation needle.
[0096] Although in the above described embodiments the energy
application part comprises an RF electrode, the energy application
part can also comprise another element for applying energy in
another way. For example, the energy application part can be
adapted to apply optical energy, for instance, for optically
ablating tissue, or the energy application part can comprise an
element for applying cold to the object, in particular, for
performing a cyro-ablation.
[0097] Although in the above described embodiments the object, to
which energy is applied, is a part of a living being, like a tumor
or like cardiac tissue, in other embodiments the energy application
apparatus can be adapted to apply the energy to a technical
object.
[0098] Other variations to the disclosed embodiments can be
understood and effected by those skilled in the art in practicing
the claimed invention, from a study of the drawings, the
disclosure, and the appended claims.
[0099] In the claims, the word "comprising" does not exclude other
elements or steps, and the indefinite article "a" or "an" does not
exclude a plurality.
[0100] A single unit or device may fulfill the functions of several
items recited in the claims. The mere fact that certain measures
are recited in mutually different dependent claims does not
indicate that a combination of these measures cannot be used to
advantage.
[0101] Provisions like the provision of the object representation
and the provision of the energy application element representation
and determinations like the determination of the positions and
orientations of the energy application element performed by one or
several units or devices can be performed by any other number of
units or devices. The provisions and determinations and/or the
control of the energy application planning apparatus in accordance
with the energy application planning method and/or the control of
the energy application apparatus in accordance with the energy
application method can be implemented as program code means of a
computer program and/or as dedicated hardware.
[0102] A computer program may be stored/distributed on a suitable
medium, such as an optical storage medium or a solid-state medium,
supplied together with or as part of other hardware, but may also
be distributed in other forms, such as via the Internet or other
wired or wireless telecommunication systems.
[0103] Any reference signs in the claims should not be construed as
limiting the scope.
* * * * *